projects/stargazer/plugins/capture/cap_debug/ip.c

   1 /* $Id: ip.c,v 1.1 2005/12/12 18:14:22 nobunaga Exp $
   2
   3 Copyright (C) 2002 Marc Kirchner <kirchner@stud.fh-heilbronn.de>
   4
   5 This library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Lesser General Public
   7 License as published by the Free Software Foundation; either
   8 version 2.1 of the License, or (at your option) any later version.
   9
  10 This library is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13 Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public
  16 License along with this library; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18 */
  19
  20 #include "libpal.h"
  21
  22 int
  23 pkt_ip_header(struct packet *pkt,
  24                 unsigned int iphdr_len,
  25                 unsigned int version,
  26                 unsigned char tos,
  27                 unsigned short int total_len,
  28                 unsigned short int id,
  29                 unsigned short int frag_off,
  30                 unsigned char ttl,
  31                 unsigned char protocol,
  32                 unsigned short int cksum,
  33                 unsigned int saddr,
  34                 unsigned int daddr)
  35 {
  36         struct ip *ip;
  37
  38         if (!pkt)
  39                 return EPKTINVALPTR;
  40
  41         ip = (struct ip *) pkt->pkt_ptr;
  42
  43         ip->ip_hl = iphdr_len;
  44         ip->ip_v = version;
  45         ip->ip_tos = tos;
  46         ip->ip_len = htons(total_len);
  47         ip->ip_id = htons(id);
  48         ip->ip_off = htons(frag_off);
  49         ip->ip_ttl = ttl;
  50         ip->ip_p = protocol;
  51         ip->ip_src.s_addr = saddr;
  52         ip->ip_dst.s_addr = daddr;
  53
  54         return 0;
  55 }
  56
  57 int
  58 pkt_ip_option_header(struct packet *pkt, unsigned char type, unsigned char len, unsigned char ptr, unsigned char oflw_flg, void *optval, size_t optlen)
  59 {
  60         unsigned char *vp;
  61
  62         if (!pkt)
  63                 return EPKTINVALPTR;
  64
  65         vp = pkt->pkt_ptr;
  66         *vp = type;
  67         switch (type) {
  68                 case PKT_IP_OPT_END:
  69                         break;
  70                 case PKT_IP_OPT_NOP:
  71                         break;
  72                 case PKT_IP_OPT_SEC:
  73                         if ((pkt->pkt_pos + 2 + optlen) <= pkt->pkt_size) {
  74                                 *(vp+1) = len;
  75                                 memcpy((void*)(vp+2), optval, optlen);
  76                         } else {
  77                                 return EPKTRANGE;
  78                         }
  79                         break;
  80                 case PKT_IP_OPT_RR:
  81                 case PKT_IP_OPT_LSRR:
  82                 case PKT_IP_OPT_SSRR:
  83                 case PKT_IP_OPT_SID:
  84                         if ((pkt->pkt_pos + 3 + optlen) <= pkt->pkt_size) {
  85                                 *(vp+1) = len;
  86                                 *(vp+2) = ptr;
  87                                 memcpy((void*)(vp+3), optval, optlen);
  88                         } else {
  89                                 return EPKTRANGE;
  90                         }
  91                         break;
  92                 case PKT_IP_OPT_TS:
  93                         if ((pkt->pkt_pos + 4 + optlen) <= pkt->pkt_size) {
  94                                 *(vp+1) = len;
  95                                 *(vp+2) = ptr;
  96                                 *(vp+3) = oflw_flg;
  97                                 memcpy((void*)(vp+4), optval, optlen);
  98                         } else {
  99                                 return EPKTRANGE;
 100                         }
 101                         break;
 102                 default:
 103                         return EPKTUNKNOWNTYPE;
 104         }
 105         return PKTOK;
 106 }
 107
 108 int
 109 pkt_ip_cksum(struct packet *pkt)
 110 {
 111         /*
 112         * checksum should be calculated by kernel
 113         * when we are using SOCK_RAW access.
 114         */
 115         struct ip *ip;
 116
 117         if (!pkt)
 118                 return EPKTINVALPTR;
 119
 120         ip = (struct ip *) pkt->pkt_ptr;
 121         ip->ip_sum = 0;
 122         ip->ip_sum = in_cksum((unsigned short *)ip, sizeof(struct ip));
 123         return 0;
 124 }